Campers in the western South Island are being warned of a wet New Years.

MetService meteorologist Emma Blades said from the late afternoon on New Years Eve until early on New Years Day severe rain falls are on the way - mainly on the West Coast.

"A total of around 200 millimetres for places around the ranges, but also close to the coast were expecting 80 to 100 millimetres. When you get rain like that, you could get rivers and streams rising rapidly."

MetService is also predicting strong northerly gales from Marlborough to the Wairarapa from early on New Years Day.